Spray gun



R.i L. POTTER Nov. 17, 1936.

SPRAY GUN Filed May 5, 1954 Patented Nov. 17, 1936 PATENT osFFlcE2,050,894 SPR-AY GUN Russelli L. Potter, Toledo, Ohio, asslgnor to TheDel Vilbiss Company, Toledo, milo, a corporation of Ohio 4ApplicationMay 3, 1934, Serial No. 723,737

12 Claims. (Cl. 299-11401) This invention relates to spray-guns of thetype employed for discharging surface coating materials in spray-form,and pertains more par-v ticularly, but not exclusively, to guns of thischaracter adapted to discharge a fan-shaped spray streaml A An importantobject of the invention resides in the manner employed for directing andcontrolling the supply of air under pressure to the main andsupplemental air discharge orices of the gun head, and particularly thesupply to said supplemental orifices, whereby the pressure of the airdischarging from such orifices is uniform irrespective of the headadjustment or conditions of USS.

Further objects and advantages of the inven ltion of a spray-gunembodying the invention,

with parts in full; Fig. 2 is a'n enlarged section on the line 2 2 inFig. l; Fig. 3 is an enlarged perspective view of the baille meansemployed for uniformly distributing the air supply to the supplementaldischarge orifices; Fig. 4 is an enlarged longitudinal section, withparts in full, of the valve means employed for controlling the supply ofair to the spray-head, and Figs. 5 and 6 -are different details of suchmeans. l

Referring to the drawing, A designates the body or stock having at itsrear end the lateral projecting handle B, and at its forward endtheenlargement C to which the spray-head D is atvtached.

Extending rearwardly through the body A from the upper portion of theenlargement C is a bore I for the passage of air, as hereinafterdescribed,

vand below the forward end of such bore centrally orifice 6 inconcentric relation to the material dispointof connection with the bodyenlargement C.

Aand the" nozzle 4 is engaged at' its outer rear edge by a union nut 8,which threads on a tubular excharge passage I 0, which orifices directjets of air tension 9 of the enlargement C concentric to the innernozzle. The outer nozzle 4 is provided at each of diametrically oppositesides of its main discharge orifice 6 with a supplemental air disinopposed relation against the combined air and lmaterial streamdischarging from the inner nozzle 3 and orifice 5, as well understood inthe art. The inner ends of the passages IU communicate with an annularpassage I l provided in the nozzle i at lo the outer side of the pointof connection of such nozzle with the ange l, so that there is nocommunication between the passage I I and the inner annular air passage5, which latter communicates with the orifice t. l5

As is customary with spray-heads of this charl1 acter, the outer nozzleii is adapted to have rotatable adjustment with respect to theinner'nozzle, so as to flatten the spray stream in any plane desired tosuit the work to be performed.

The tubular extension 9 on the enlargement Cis spaced radially from theinner nozzle il and the portion of the enlargement C into which itthreads to form an annular space therebetween, which space is dividedinto inner and outer annular chambers I2 and i3 by a tubular member lil,which has its rear end thrust against a coacting portion of theenlargement C and its forward end thrust against the flange l of theinner nozzle. The member lil is centered with respect to the innernozzle by seating at its forward end over an annular shoulder on theflange l, as shown. The inner chamber I2 has communication with thepassage 5 through a plurality of openings I5 provided in the flange l,and the outer chamber I3 has communication at its forward end with theannular passage I I from which the supplemental discharge passages I0receive their air supply.

The outer'chamber I3 receives its air supply at its rear end through apassage I6, which registers with the forward end of the body bore I andcommunicates therethrough with a source of air pressure supply, ashereinafter described.

In order to provide an even distribution of air under pressure to bothsupplemental discharge passages I0 under all conditions, the member I4is provided at its outer side, within the chamber I3, with a pluralityof successively disposedvbailles, in the present instance, in the formof annular flanges I1, I8 and I@ (see Fig. 3), each havingdifferentially arranged orifices therethrough, and which at their outeredges engage the tubular exltension 9, so as to divide the chamber I3into a tion of the bore I at its forward end to provide a In order toeect a thorough equalizing of the air pressure entirely around theforward end of the chamber I3 before entering the annular passage IIF,the rear baille flange I'I is provided with one or more orificesI'Ia atopposite sides of the head axis and substantially a quarter way aroundin each direction from the air supplypassage I6.- The next flange I8 isprovided equidi'stantly therearound with four notches I8, two of whichare above and two below the orifices I'I'. The

last flange I9 is provided with a plurality of equidistantly spacedorifices |911 of greater number the forward endpf the bore I through anannular` passage 2U and segmental passage 2| v`provided in theenlargementC 'concentrically of the bore 2, the passage 20 extendingthrough the bottom por'- port connection 22 therebetween.

A passage 25 is provided in the handle B forv connectionin any suitablemanner, with a source of air pressure supply, and its passage. hascommunication with a port 26 opening` laterally into the rear endportion of the borev I.. A main normally closed shut-off valveZI isprovided in the passage 25, being opened by an operation of the trigger28, as well understood in the art.

The bore I opens without the rear end of the gun body A andreceivesthrough such end a tube 30, which is threaded at its forward endin a slightly restricted portion of the bore I in advance of the port 22with the forward end of its passage in communication with the orifice I6.

. through which air is supplied to the chamber I3,

which latter maybe considered as a pressure equalizing chamber. .Therear end of the tube 3Il is provided with an enlargement 3| that iitssnugly in the rear end of the bore I, and without the rear end .of thebore the. tube is provided with a further enlargement 32 that is adaptedtoshoul der against the marginal end wall of the bore and preferably hasa portion of its periphery of hexagonal or other suitable form forengagement bya wrench to facilitate n turningnf the tube into or' out ofthreadedengagement at its forward end with the body enlargement C.

While the enlargement C has been referred to, in effect, as beinga lpartof the body A, it, in

. reality, constitutes a head construction which is separable from thebody A and is secured thereto-by thetube 30,.which acts as a. bolt orrod for rigidly connecting the two parts of the gun body. Thisis afeature, which, in itself, `forms no par of thepresent invention. I

In order to prevent the tube .out of the bore I and thus becomingseparated from the gun body when the head construction C,

D, is removed from the gun, the threaded end Vof the tube is slightlyenlarged relative to theiadjacent portion thereof and the bore isprovided in the body A adjacent to its point o'f connection with thehead C with a reduced threaded'portion 33, thus requiring the vtube tobe unthreaded through such portion when being 'removed from the body.lihe tube 3l) intermediate the inlet port yrelative to` the tube. l 1

:n.frin failing.

26 and outlet port 22 is smaller than the bore I, so as to permit air topass through the bore around the tube from one of said ports to theother. It is thus apparent that the only control for the air passing tothe main air discharge oriiice '6 of the spray-head is the main valve21.

The tube 30 near. its rear end portion has cornmunication with the airspace around the tube 'through ports 34, so that the supply of air. forthe supplemental discharge orifices III of the spray-head is furnishedthrough the tube.

air for this purpose is controlled by a valve 35,

which, in the presentinstanoe, is of tapered form and adapted to seat ina restricted portion of the tube passage provided slightly in advance ofthe ports 34 in the tube. The valve-stem is provided at its rear endportion withan enlargement 36 (Fig. 4), which in turn is providedvintermediate its ends with a.. further enlargement31 that isthreadedinto the rear end of the tube 30, so that a turning of the valve-stem'relative to the y tube will effect an advance or retracting of the valverelative to its seat. The outer end of the steml 36 projects from therear end of the tube through asuitable packing gland 38 and is providedat its outer end Awith a knurl'ed head 39 to facilitate turning.

It is desirable to provide some means for effecting a drag. against afreeV turning of the valve-stem 36 so that the valve may not'beaccidentally movedfrom an adjusted setting found desirable for theparticular spraying operation in hand. While it is not newvto provide adrag onl a valve of this character, the means heretofore Yemployed foraccomplishing this have, so far as I am aware, been unsatisfactory andimpractical for many classes of work. /An efcient means foraccomplishing such a drag consists in mounting a skirt member 40 onthe'valve-stem 36 in ivance of the threaded portion 31 and having its.,Qrward end slotted to provide spring fingers 4I which normally exertan outward pressure against the wall of the tube 30 and thus exert aconsiderable drag against a turning of the valve Another detailedconstruction of the valve mechanism .that is of importance in connectionlwith a tool of this character is the provision of an adjustable dialmember in connection-with the control headv 39 o'f thel valve. Thismember comprises "a --normal slightly cupped disk .45,

which is held Afor rotatablel adjustment within the outer recessed endof the valve-head by a screw 46. The edge of the disk is in contact withl the bottom of the head recess and it is substanltially flattenedagainst the head by a tightening of the screw. The' disk is ofv springmetal, so

'that when nattened, or. partially' flattened by the 4engagement ofr thescrew, a `suillcient binding action is provided between the valve-headand screw to prevent a. free turning of the The disk is provided withgraduations which.v are' adapted to register with some stationary point'on the gun body to indicate the extent of turn-v ing adjustment. ofthevalve-head relative to the body. It is found inl pracctice that, due`to variations in'the machining of the various parts involved, it wouldbe quite'diicult and expensive to make -the'threading engagement ofthetube. 38 with the spray-head body, and the valve-stem with said tube,and other relative dimensions rof -the various parts,-so exact that avfixed dial on the valve and a marker-line on the body would bear thesame relation in anumber of guns for .the same amount .of valveopeninl'g.l Itgis also accesos found that there is considerableobjection to removingvalves after determining how they set in the valvebody and then marking them. Replacement valves would also be a problemif such procedure were followed. These objections are obviated and theproper adjustment of the valves made simple and more or less permanentby theuse lof a dial disk d frictionally held to the valvehead. `Withthis design of movable dial, should wear ofthe valve or the valve-seatalter the standard original setting between the dial and the body mark,the dial may be easily and quickly reset to correspond to the originalsetting. To facilitateadjustment of the dial, a hole dfi is providedtherein into which a pointed tool may be inserted.

.Tit will be) appreciated from the foregoing that in the use of myimproved spray-gun, the operating air is supplied to the main andsupple- 'mental discharge orifices of the spray-head through distinctpassages provided through a common bore in the gun body; that the air tothe supplemental discharge orifices is controlled in a simpleandconyenient manner separate from the control means for the main airsupply; jthat such control is located near the rear end of the gun bodywhere it is convenient of access, and

that the air for the supplemental discharge orifices passes through a.pressure equalizing chamber in the spray-head before reaching suchorifices, so that the pressure is uniform in its discharge from bothoriflces irrespective of the position oi such orifices. This latter isan `iinportant feature, as it obviates the objection frequentlyencountered in the use of spray-guns,

that the pressure of air discharging from the two supplemental orificesvaries, thus effecting the stream flattening emciency of such air.

It is further apparent that with the present invention the tube 30 notonly constitutes a means for' detachably uniting thev body A andsprayhead portion C, D, of the gun, but also forms a v passage for theairto a predetermined portion of the spray-head and constitutes with thecontrol valve an assembly which is removable as a unit. from. the gun.It will be understood in practice that the valve 35 is set to suit the'desired volume and pressure discharge of' air from the supplementalorifices to` suit the particular communication therewith, a memberextended` throughsaid bore in shouldered engagement with a part thereofand having releasable engagement with the spray-head to unite the bodyand spray-head in assembled relation, said main and supplemental orificedistributing chambers having respective communication, onevthrough saidbore and the otherthrough said. member, with'- said supply passage,andmeans associated withone of said passages for controlling the supply ofair passing therethrough to the'supplemental orice's '2. In a spray-gun,a body having a-longitudinally extending bore therein, a spray-headdetachably carried by the body and having main tion,

'adapted to have communication with a source ,lar member extendingthrough said bore' in engagement with a part thereof and havingengagement at its forward end with the spray-head to retain the body andhead in assembled relasaid main and supplemental passages of .airpressure supply, one through said bore and the other through saidmember, and valve means cooperating with one of said passages to controlthe supply of air to the supplemental orifices.

3. In a spray-gun. a body having a longitudinal bore therethrough and apassage adapted Ito open communication between said bore and a source ofair pressure supply, a spray-head detachably carried by said body andhaving main and supplemental air discharge orifices, a tubular memberextended through said bore in coaction with a portion of the body andhaving threaded engagement at its forward end with 'the spray-head toretain the body and sprayhead in assembled relation, said main andsupplemental discharge orifices having respective communicationthrough`said bore and tubular member with said supply passage, and avalve mounted in said tubular member and operable from without the rear`end of said member and bore to control the supply of air to saidsupplemental orinces.

e. lin a spray-gun, a body having a longitudinal bore therethroughy anda passage adapted to open communication between said bore and a sourceof air pressure supply, a spray-head detachably carried by said body andhaving main and supplemental air discharge orifices, a tubular memberextended through said bore in shouldered coaction with a portion of thebody and having threaded engagement at its forward end with thespray-head to retain the body and-` .spray-head in assembled relation,said main and supplemental discharge orifices having respectivecommunication through said bore and tubular member with said supplypassage, and valve charge orifices, said main orifice having com-'munication with the forward end of said longitudinal passage to receiveits air supply therefrom, a tubular member mounted in said longitudinalpassage and"having detachable-engagement with lthe spray-head to retainthe sprayhead and body in assembled relation, said meml itself havingcommunication at its forward end .with the supplemental dischargeorifices and at its rear end portion with a portion of the gun bodythrough which air under pressure is supplied to said longitudinalpassage.

6.' In a spray-gun, a gun body, a spray-head, a tubular member projectedthrough the body and operable to unite the body and head in assembledrelation and vforming an air supply passage to a portion of thespray-head, a valve mounted in said member to control the passage of airtherethrough and having a stem part projecting without the rear end ofthe tube and threaded in the tube, whereby a turning of the stem. eectsan adjustment of the valve, and

said member ,to resist a turning-of the stem.

7. In a spray-gun, agun body, a spray-head carried thereby" and havingmaink and supplemental air discharge orifices and4 separatefair chamberstherefor, said body having a bore extending rearwardly from the'spray-head with its forward end in communication with one, oi

said chambers and its rear end in communication" with a source of airpressure supply, a tube vi-gterial'supply throat in its forward en d, amaterial dischargenozzle projecting from said throat and having anannular `flange in advance of the body fpart,` "said` lpart having vanannularabutment v\'flangerearwardly of said `no'zirlel iiange and a`forv'vard extension without saidjabutnijent flange mounted in saidbore-and forming a separate passage from the .bore in communication atits' forward end with the other of said chambers;v and at its rear endwith the source of air pres-` sure supply, and means associated Vwithsaid tube.- to lregulate the volume of air passing theref'vr yanduoutwardlyspaced withrespectet' a tubular 'member in abutment atfitsA lends with said flanges and dividing. the space .betweensfaidhaving main and supplemental air discharge orifices and a separate airchamber for each, said y 8'. In aspray-gun, a gun body, a spray-head(carried by the body at its forward end, said head body having a boreextending rearwardlytherein from adjacent the spray-head and forming anair passage. with its forward end in communisages having communicationrearwardly of the head with an air pressure supply source.

9. In a spray-gun, a gun body, a spray-head carried by the body at itsforward end, said head having main and supplemental air discharge oricesand a separate air chamber for each, said body having a bore extendingrearwardly therein from adjacent the spray-head and forming an air`.passage with its forward end in communicationwith one of said chambers,a tube extending rearwardly in .said bore from adjacent the sprayheadand forming 'a second air passage with its forward end in communicationwith the other and aiseparate means for regulating the passage l of airthrough one of said passages.

10. In a spray-gun, a gun body having a sprayhead at one end and ahandle at the other end,

said head having main andsupplementalair discharge orifices and separateair supply chambers therefor, said body having a bore v'extendingrearwardly from adjacent the head and forming an air passage with itsforward end incommunication with oneof said chambers, a tube on, saidbore` forminga secundair passage with it'sffforward 'end incommunication with the otherfof said chambers. said passages adapted'forcommon f communication at theirgrear end"portions with .an'air pressuresupply source through said handle, a main control valve carried by thevhandle for .thesupplyof air to saidpassages, anda second `control. valvemounted in the rear end of said -,bore `and controlling the passagethrough said -..tube. 1g= l lll In a spray-gun, 'a bodypart having a ma-"aid nozzle,

end of said inner nozzle and havingrearward abutment against said firstannular flange and g providing a main discharge orifice, said outernozzle also having ,supplemental air discharge passages, and meansreleasably joining the outer nozzle to the body. part, said main Vairdischarge.

orifice having communication through saidinner air` chamber and saidsupplemental passages having baffled communication through said outerchamber with a source of air pressure supply.

'12, AIn a spray-gun, a body part having a material supply throat in itsforward end, an annular extension without said throat and concentricthereto and an annular abutment internally and rearwardly of saidextension, an inner material discharge nozzle projecting from saidthroat and having an annular flange in advance of said abutment; atubular member in opposite end abutment with said -'ange and abutmentand dividing thespace between-said nozzle andextension into inner andouter air chambers, a plurality of anges on said member dividing saidouter'chamber into a plurality of annular passages having staggeredcommunication with each otherthrough the flanges, an outer air dischargenozzle in rearward abutmentagainst said first flange and having a main'vair dischargejorifice associated with lthe inner nozzle discharge andhaving supplemental air discharge orifices, said J- v main orice havingcommunication .through said inner air chamber and said supplementaloriceshaving batlied communication through .said outer air chamber witha sourceV of air pressure supply. i

- RUSSELL L. POTTER.

